I dunno how you feel about MP. Personally I wish it wasn't a factor at all in any part of the game. That said, I hate these types of 4 random d*****bag multiplayer schemes games throw at ya, BUT the ones for ME3... not so bad. There's voice chat, but seriously, no one uses it. That's a plus to me because there's nothing I hate more than "God's-Gift-to-MP-Shooters" on my team yelling at me. Hasn't happened once so far and I've been playing about 3-4 hours a day for the last 6 days. It groups people of all skill together, and to get a new, low-level on your team means GOOD things since the enemy won't be as hard as all high-levels on a team.
Sure, I've played with people who don't revive anyone... ever, but they are an exception. I've played with some people that never moved (and somehow never died although they stood there). I've ran across one person who kept getting head-shot kills on targets they weren't even shooting at.... umm, I guess what I'm saying is there are some cheaters out there... BUT, not many. Not enough to make the MP part of ME3 completely horrible.
I've played almost every class now. Good at Infiltrator, okay at Vanguard, Awesome at Engineer (easy to be awesome at Eng), and downright sucking at soldier. But it's totally different than what I thought it would be like. No yelling. No one b**ching at anyone else. Hey, if you loose, you can leave, no one's stopping anyone. It's actually an okay pass-time when you're a little bored of single player, and you can get your Galactic Readiness to 100% pretty quickly. GR will slowly drop over time when you're not doing MP, but at the end of SP before you go to earth, you can pop into MP for a couple of games and get back to 100% fast.
NOW, all that said... the asset cheat works fine as long as you only use it on One faction, alliance being easiest since it's usually the highest to start with. But, if you're struggling because you messed up somewhere, the MP isn't as bad as you may think it is.
*also note* I only have played Bronze level, I do not know if the Silver and Gold is where the a**holes lurk. You also don't need silver/gold for Galactic Readiness.